1. Field of the Invention
The present invention relates to an implement and more particularly to an implement which is adapted to be borne by a vehicle, such as a tractor, in earth traversing movement and to be extended and alternately retracted during the performance of the work operation in response to a predetermined stimulus requiring minimal supervision by the operator and to such an implement in which the work performing portions thereof are activated only upon reaching predefined work performing positions.
2. Description of the Prior Art
It is frequently necessary in farming to perform a variety of work operations with respect to the crops which are inherently dangerous, but are nonetheless essential to a productive and efficient farming operation. For example, it is periodically necessary in the farming of vine borne crops such as grapes to sever the lowermost canes and foliage of the vines for proper conditioning and so the canes will not become entangled in other equipment which might damage both the vines and the equipment. Cane cutters borne by tractors are employed for this purpose and operate to sever the canes on the opposite sides of each row a distance of approximately one to two feet above the earth's surface. Such cane cutters are passed at the desired elevation along the ground along horizontal paths of travel throughout the length of the row. During such travel and particularly upon entry to and exit from each row, the cutters must be carefully maneuvered so as to avoid inadvertent injurious contact with other portions of the vines and other objects in the vicinity. Caution must also be exercised to avoid injury to passersby either by contact with the cutting blade itself or by fragments of material thrown by the cutting blade.
Because of the inherent danger in the use of cane cutters, it has been, in most instances, inappropriate to perform other work operations, such as cultivating, during the use of the cutters even where both operations could otherwise be performed at the same time. This requires either the expenditure of considerably more time to perform both operations than would be desirable, or disregard for the risks inherent in simultaneous performance of these operations.
In any case, these problems have, in the past, interferred with the efficient use of the equipment and created a risk of injury of the type to which recent industrial and agricultural safety legislation has been directed.
Therefore, it has long been known that it would be desirable to have an implement which operates efficiently and dependably to perform its work operation with minimal supervision while minimizing the risk of injury to field workers, crops and other objects in the vicinity and which permits several work operations to be performed simultaneously with little or no additional supervision.